BIPHETAMINE 20
Clinical safety rating
cautionComprehensive clinical and safety monograph for BIPHETAMINE 20 (BIPHETAMINE 20).
Biphetamine 20 is a fixed-dose combination of amphetamine and dextroamphetamine, which are non-catecholamine sympathomimetic amines that promote the release of dopamine and norepinephrine from presynaptic neurons, and inhibit their reuptake, thereby increasing synaptic concentrations of these neurotransmitters in the central nervous system.
| Metabolism | Metabolized primarily by the liver via CYP2D6 and to a lesser extent by CYP3A4. Major metabolic pathways include hydroxylation, deamination, and oxidation to benzoic acid derivatives. Excretion is primarily renal. |
| Excretion | Renal (90% as unchanged drug and metabolites, with approximately 30% unchanged); fecal (10%) |
| Half-life | 0.5–1.5 hours for the immediate-release component; terminal elimination half-life of the total amphetamine salts is approximately 10–13 hours in adults |
| Protein binding | 16–20% (primarily to albumin) |
| Volume of Distribution | 3–4 L/kg; indicates extensive tissue distribution |
| Bioavailability | Oral: 75–100% (first-pass metabolism minimal) |
| Onset of Action | Oral immediate-release: 30–45 minutes; oral extended-release (biphetamine 20): 1–2 hours |
| Duration of Action | Oral immediate-release: 4–6 hours; oral extended-release (biphetamine 20): 8–12 hours |
| Molecular Weight | 135.21 |
10-20 mg orally once daily in the morning; may increase to 20 mg twice daily (morning and noon) if needed.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | eGFR <30 mL/min: contraindicated; eGFR 30-59 mL/min: use with caution, reduce dose by 50%. |
| Liver impairment | Child-Pugh class A: no adjustment; Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: use not recommended. |
| Pediatric use | Children ≥6 years: initial 5 mg orally once daily; titrate by 5 mg weekly to max 20 mg/day. |
| Geriatric use | Initiate at 5 mg orally once daily; increase slowly with monitoring for cardiovascular effects. |
| 1st trimester | Biphetamine is a controlled substance containing dextroamphetamine and amphetamine. Use in first trimester is not recommended due to increased risk of congenital malformations, particularly cardiac defects and oral clefts, based on limited human data and animal studies. Consideration only if potential benefit outweighs risk. |
| 2nd trimester | Use in second trimester is associated with potential risks of preterm delivery, low birth weight, and neonatal withdrawal. Monitor fetal growth and development. Avoid unless absolutely necessary. |
| 3rd trimester | Use in third trimester may cause neonatal withdrawal syndrome (irritability, poor feeding, hypertonia) and increased risk of preterm birth. Avoid use, especially near term. |
Clinical note
Comprehensive clinical and safety monograph for BIPHETAMINE 20 (BIPHETAMINE 20).
| Placental transfer | Amphetamine and dextroamphetamine cross the placenta readily. Human data show cord blood concentrations approximately equal to maternal plasma concentrations, indicating significant placental transfer. |
| Breastfeeding | Biphetamine is excreted into breast milk. Use during breastfeeding is not recommended due to potential for infant stimulation (irritability, poor sleep) and growth impairment. If use is necessary, monitor infant for adverse effects. The American Academy of Pediatrics considers amphetamines as drugs that are contraindicated during breastfeeding. |
| Lactation Rating | L5 (Contraindicated) |
| Teratogenic Risk | First trimester: Limited data; possible increased risk of oral clefts and cardiovascular defects based on some studies. Second and third trimesters: Risk of prematurity, low birth weight, neonatal withdrawal syndrome, and potential for behavioral effects. Avoid use unless benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and weight. Fetal ultrasound for growth and development. Neonatal monitoring for withdrawal symptoms (tremors, feeding difficulties, irritability) if used near term. |
| Fertility Effects | No well-controlled studies; may impair fertility in females due to anovulation or hormonal changes. Use weight loss may affect menstrual cycle. Limited data on male fertility. |
■ FDA Black Box Warning
WARNING: ABUSE AND DEPENDENCE. Biphetamine contains amphetamine and dextroamphetamine, which have a high potential for abuse and dependence. Prolonged use may lead to drug dependence. Misuse may cause sudden death or serious cardiovascular adverse events.
| Serious Effects |
Hypersensitivity to amphetamine or any component of the formulationAdvanced arteriosclerosisSymptomatic cardiovascular diseaseModerate to severe hypertensionHyperthyroidismGlaucomaAgitated statesHistory of drug abuseDuring or within 14 days of MAO inhibitor therapy (hypertensive crisis risk)
| Precautions | Cardiovascular: risk of sudden death or serious cardiovascular events, especially in patients with pre-existing cardiac abnormalities., CNS effects: may cause psychotic or manic symptoms, aggression, seizures, and visual disturbances., Growth suppression: may cause weight loss and growth retardation in children., Peripheral vasculopathy: including Raynaud's phenomenon., Serotonin syndrome: when co-administered with serotonergic drugs., Potential for immediate hypersensitivity reactions. |
| Food/Dietary | Avoid foods and beverages high in caffeine or other stimulants (e.g., coffee, tea, cola, chocolate) as they may increase stimulant effects and risk of adverse reactions. Acidic foods (e.g., citrus fruits, juices) and vitamin C can decrease absorption; separate intake by at least 1 hour. Maintain a consistent meal schedule to minimize appetite suppression. |
| Clinical Pearls | Monitor for hypertension and tachycardia; avoid use in patients with cardiovascular disease, hyperthyroidism, or glaucoma. Use with caution in patients with a history of substance abuse. May exacerbate tics and Tourette syndrome. Do not administer late in the day due to insomnia risk. Discontinue if seizures occur. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency without consulting your doctor. · Take the first dose upon awakening; avoid taking late in the day to prevent sleep problems. · Do not chew or crush tablets; swallow whole with water. · Avoid alcohol and caffeine while taking this medication. · Report any chest pain, palpitations, shortness of breath, or fainting immediately. · May cause dizziness or blurred vision; avoid driving until you know how it affects you. · Store at room temperature away from light and moisture. |
Loading safety data…